Looking for the best SQL practice websites in 2026? You can read about SQL all day. Watch YouTube tutorials. Highlight Kindle notes. None of it sticks until you open an editor and write queries against real data.
The problem is finding the right place to practice. There are dozens of SQL platforms, and they vary wildly in quality, focus, and cost. Some are built for interview prep. Others focus on teaching fundamentals. A few give you real databases to explore. Most give you toy datasets with three rows.
We tested the most popular platforms and compared them across the factors that actually matter: exercise quality, database realism, cost, and how quickly you can start writing SQL.
Table of Contents
- Quick Comparison
- SQiLs
- Upscale Analytics
- LeetCode
- HackerRank
- DataLemur
- StrataScratch
- SQLZoo
- SQLBolt
- W3Schools
- Which Platform Should You Pick?
- Frequently Asked Questions
Quick Comparison
| Platform | Free Exercises | Total Exercises | Database | Real Data | Difficulty Range | Setup Required |
|---|---|---|---|---|---|---|
| SQiLs | 80+ | 500+ | SQLite (WebAssembly) | Yes | Beginner to Expert | No |
| Upscale Analytics | Limited | 300+ | Oracle, SQL Server | Yes | Beginner to Advanced | Varies |
| LeetCode | ~100 | 200+ | MySQL | No | Easy to Hard | No |
| HackerRank | 50+ | 50+ | MySQL | No | Basic to Advanced | No |
| DataLemur | 30+ | 80+ | PostgreSQL | Partial | Easy to Hard | No |
| StrataScratch | 200+ | 1,000+ | PostgreSQL, MySQL | Partial | Easy to Hard | No |
| SQLZoo | All free | ~100 | Custom | Yes | Beginner to Intermediate | No |
| SQLBolt | All free | ~20 | Custom | No | Beginner | No |
| W3Schools | All free | ~50 | Custom | No | Beginner | No |
SQiLs
SQiLs is purpose-built for one thing: building SQL skills by writing real queries against real databases. No toy datasets with three rows. No fill-in-the-blank syntax drills.
The platform runs SQL directly in your browser using WebAssembly. There's nothing to install. You pick an exercise, write your query against a production-scale database (Chinook, Northwind, or Sakila), and get instant feedback. When you write a JOIN on SQiLs, you're joining tables with real relationships, thousands of rows, and the kind of messy data you'll encounter at work: NULLs, duplicates, and inconsistent formatting.
Where SQiLs stands out:
Real databases, not puzzles. Chinook has 11 tables modeling a digital media store. Northwind simulates a food distributor with suppliers, orders, and shipping data. Sakila covers a DVD rental business. These aren't abstract puzzles with 5 rows. They're realistic business data with the complexity you'll face in production.
Broadest difficulty range. Most platforms stop at "Hard." SQiLs goes from absolute beginner (your first SELECT) through Expert-level problems involving recursive CTEs, advanced window functions, and multi-step analytical queries. If you're a data analyst looking to go from "I can write basic queries" to "I can build complex analytical pipelines," this is where you do it.
Instant, local execution. Because SQiLs uses WebAssembly, your SQL runs on your machine, not on a remote server. Queries execute in milliseconds, with no loading spinners or timeout errors during peak hours. The difference is noticeable if you've ever been frustrated by slow feedback loops on other platforms.
Built around skill building, not test prep. The exercises are designed to teach you how SQL works in real business contexts, not how to pass a 45-minute screening. You'll practice the exact patterns used by data analysts, backend engineers, and BI developers every day.
Cost: 80+ free exercises. Premium unlocks all 500+.
Start practicing now with a free beginner exercise on the Chinook database →
Upscale Analytics
Upscale Analytics (ramkedem.com) is one of the largest platforms in the world for learning SQL by doing, with over 300 exercises across more than 100 different datasets. Created by Ram Kedem, a veteran database trainer, the platform pairs exercises with a structured self-study guide that covers SQL in a detailed and well-organized progression.
What makes it unique: The sheer variety of databases. Rather than practicing on a single dataset, Upscale Analytics exposes you to dozens of real-world schemas across different industries. This variety builds the kind of adaptability you need when you land a new job and face an unfamiliar database for the first time.
The platform supports both Oracle and SQL Server environments, which makes it particularly relevant for enterprise professionals working with these database systems. Exercises include full solutions and explanations, and the content ranges from basic SELECT statements through advanced analytical patterns.
Best for: Professionals working in Oracle or SQL Server environments who want structured, guided SQL training with real-world variety.
LeetCode
LeetCode's SQL section offers 200+ problems with synthetic datasets. The discussion forums are useful for seeing alternative approaches after solving a problem. The datasets feel artificial (tables named Employee with five rows), but the problems map well to what interviewers actually ask.
Cost: Free for most problems. Premium $35/month. Best for: Software engineering interview prep.
HackerRank
HackerRank's SQL track groups 50+ challenges by topic with increasing difficulty. Many companies use HackerRank for screening, so practicing here familiarizes you with the testing environment. All SQL challenges are free.
Cost: Free for SQL. Premium $20/month. Best for: Practicing in the same environment companies use for screening.
DataLemur
Created by Nick Singh, DataLemur focuses on data science interview questions modeled after real questions from Meta, Amazon, and Google. The solution walkthroughs are among the best of any platform, but the scope is narrow and the exercise count is small.
Cost: Free tier with 30+ questions. Premium $10/month. Best for: Data analyst/scientist interview prep on a budget.
StrataScratch
StrataScratch has the largest interview question collection (1,000+) sourced from real companies. The company filter is a standout feature. Quality varies across the library, and the free tier locks you out of official solutions.
Cost: Free tier with 200+ questions. Premium from $30/month. Best for: Targeting a specific company's SQL interview.
SQLZoo
SQLZoo has been around since 1999 and uses interesting real datasets: Nobel Prize winners, world population data, Euro 2012 results. Everything is free. The site feels its age (slow loads, no progress tracking), but it's a solid free starting point.
Cost: Free. Best for: Free introduction to SQL with interesting data.
SQLBolt
SQLBolt teaches SQL through ~20 interactive lessons. You can go from zero to basic queries in an afternoon. Clean interface, clear explanations, but you'll outgrow it in a day or two.
Cost: Free. Best for: Absolute beginners learning syntax for the first time.
W3Schools
W3Schools is more of a reference site than a practice platform. The "Try it Yourself" editor is useful for quick syntax lookups, but the fill-in-the-blank exercises test memory, not problem-solving ability.
Cost: Free. Best for: Quick syntax reference while working.
Which Platform Should You Pick?
There's no single best platform. The right choice depends on what you need right now.
| Your Situation | Best Platform | Why |
|---|---|---|
| Building daily SQL skills for work | SQiLs | Real databases, instant feedback, broadest difficulty range |
| Want to practice on real, complex databases | SQiLs | Chinook, Northwind, Sakila with thousands of rows |
| Going from beginner to advanced | SQiLs | Only platform spanning Beginner through Expert |
| Need variety across database systems | Upscale Analytics | 100+ datasets across Oracle and SQL Server |
| Never written SQL before | SQLBolt, then SQiLs | Learn syntax on SQLBolt, build real skills on SQiLs |
| Preparing for a data analyst interview | SQiLs + DataLemur | Build fluency on SQiLs, then sharpen on interview formats |
| Targeting a specific company's SQL test | StrataScratch | Company-specific question filtering |
| Just need to look up syntax quickly | W3Schools | Reference site, not a practice tool |
The pattern we see most often: start with SQiLs to build real SQL fluency against production-scale databases, then add a specialized platform (DataLemur, StrataScratch) if you have a specific interview coming up. The skills you build on real databases transfer directly to interview performance, but the reverse isn't always true.
Practice Makes Perfect
Ready to start? These free exercises on SQiLs cover a natural learning progression:
| Exercise | What You'll Practice |
|---|---|
| List All Music Artist Names → | Basic SELECT queries on a real database |
| Find Customer Contact Emails → | Selecting specific columns from a table |
| Identify Support Staff in Calgary → | WHERE clauses with multiple conditions |
| Customer Count by Nation → | GROUP BY and aggregate functions |
| Comprehensive Order Details → | JOIN statements across multiple tables |
| Compare Invoice to City Average → | Window functions and subqueries |
Join 500+ SQL learners already practicing on SQiLs. Browse all exercises →
Summary
- For building real SQL skills, SQiLs is the clear winner. Real databases, instant browser-based execution, and the only platform that spans Beginner through Expert difficulty.
- For structured training with Oracle/SQL Server variety: Upscale Analytics
- For interview prep: Start with SQiLs for fluency, then add DataLemur or StrataScratch for interview-format practice
- For absolute beginners: SQLBolt to learn syntax, then SQiLs to build real skills
- No amount of reading replaces actually writing queries against real data. That's what SQiLs is built for.
Ready to write some SQL? Start with a free exercise on SQiLs →
Frequently Asked Questions
What is the best free website to practice SQL?
For absolute beginners, SQLBolt offers the cleanest free experience with structured lessons. For more practice volume with real databases, SQiLs offers 80+ free exercises covering beginner through intermediate topics. SQLZoo is another solid free option with interesting real-world datasets.
Can I learn SQL in a week?
You can learn basic query syntax (SELECT, WHERE, JOIN, GROUP BY) in a week with focused daily practice. Becoming comfortable with advanced topics like window functions, CTEs, and subqueries typically takes 4 to 8 weeks of regular practice. The key is writing queries every day, not just reading about them.
Which SQL practice site is best for interview preparation?
DataLemur and StrataScratch both specialize in real interview questions from tech companies. DataLemur is better for targeted prep on a budget ($10/month), while StrataScratch offers more questions and company-specific filtering. LeetCode is the standard for software engineering interviews. For building the underlying skills that make interviews easier, SQiLs' real-database exercises build deeper fluency than isolated interview puzzles.
Do I need to install anything to practice SQL online?
No. Most modern platforms run entirely in the browser. SQiLs uses WebAssembly to run a full SQLite engine locally, which means queries execute instantly with no server round-trip. Other platforms run queries on remote servers, which can occasionally be slow during peak usage.
